One way to provide illumination is to use compact light dispersing illumination systems such as systems that employ optical components to disperse light from a light source such as an LED across a relatively wide area. Light dispersing illumination systems and components for dispersing light have been developed over the years. Some of these designs comprise a two-stage compact light disperser in which a light dispersing layer is optically coupled to a light redirecting layer. The redirecting layer includes a light-guide that guides the light laterally within the light-guide away from the light source towards the light dispersing layer by total internal reflections with almost no loss of energy. Several examples are shown in United States Patent Application Publication No. 2010/0202142, entitled “Illumination Device” which is assigned to the applicant of the present application.
One of the difficulties with some conventional compact light dispersing systems is that a relatively significant amount of heat (thermal energy) is generated at the light source, which can reduce the efficiency of electricity-to-light conversion by the source, and thus should be removed from the source during operation of the device. In order to transfer this heat away from the light source, conventional compact light dispersing illumination systems typically have the light source mounted on an outer surface of the device, attached to a large heat sink. While such designs are adequate for their intended purpose, improvements in this area may nonetheless be desirable.